Process op grinding paper-pulp



UNITED STATES PATENT OEETCE,

JOSEPH KINGSLAND, JR., OF FRANKLIN, NEVI JERSEY.

PROCESS OF GRINDING PAPER-PULP.

Speccation forming part of Letters Patent No. 16,316, dated December 28,1856; Reissued June 28, 1859, No. 744.

To all whom it may concern:

Be it known that I, JOSEPH KINGSLAND, Jr., of Franklin, in the county ofEssex and State of New Jersey, have invented a new and useful Process ofGrinding Fibrous Vegetable Matter, in Water, to Pulp in the Manufactureof Paper, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, whichmake part of this specification, and in which Figure 1 represents avertical section of a beating or stuff-engine suitable for carrying intoeifect my improved process. Fig. 2, represents an elevation of one endand Fig. 3, an elevation of the other end of the saine.

The stock from which paper of fine quality is made, usually consists ofrags varying in strength and fineness of fiber. These rags, in theprocess of manufacturing them into paper, are reduced, by grinding themin water, to a mass of pulp. The machines heretofore generally employedfor this purpose, are two in number, similar in construction, andtermed, respectively, the washing-engine and the stuft-engine. Thewashing-engine is employed to cleanse and rough-grind the rags, which,after being subjected to this operation, are called halfstuff, thestuff-engine is employed to complete the grinding of the half-stuftninto tine pulp. This stuff-engine consists of an annular trough or vat,in which a current of water, with the half-stuff to be ground floatingtherein, may be kept flowing around. This vat has a Xed grinding-bedplaced across its bottom and a revolving grinding cylinder placed abovethis bed, leaving a narrow space between the two. The face both of thebed and of the cylinder is armed with blunt steel knives, those on theface of the cylinder working past those on the face of the grinding bed,in the manner of shear blades, but so as to bruise and tear rather thancut the half-stuff, as sharp knives working as shears would tend toomuch to granulate the ber by cutting it into short lengths, instead ofcrushing it into pulp. This bed and revolving cylinder constitute thegrinder of this engine, and they also form a partition across the troughor vat. The rotary motion of the cylinder dashes the water and rags fromone side of the partition to the other, through the spaces between theknives, thus depressing the level of the water in the trough on thatside of the partition whence the water flows, and raising it on theopposite side; the water thus disturbed seeks to regain its level, byflowing from that side of the partition at which it is highest, aroundthe annular trough or vat, to the opposite side of the partition; thisestablishes a current around the vat, which continues while the cylinderis in motion, and keeps the whole mass of rags passing repeatedly"through between the knives where they are repeatedly ground, until thefiber is reduced. Tt necessarily follows, from the manner in which thisstuff-engine. operates, that the fine and the coarse, the tender and thestrong fibers are all subjected to an equal amount of grinding, andtherefore, the coarse and strong fiber must be ground too little, or thetine and tender liber too much, in either case producing a pulp ofheterogeneous quality, which will impart a corresponding defect to thepaper made from it. But as the quality of the paper is most injured byinsuiiicient grinding of the fiber, the grinding is generally continueduntil the coarse fiber is well reduced, which grinds much of the moretender fiber to powder, a portion of which flows oif with thewaste-water and is lost; another portion of it is lost at a subsequentstage of the manufacture'by draining off with the water from the screenthat transfers the pulp from the vat to the Fourdrinier machine, forconverting the pulp into sheets of paper. The loss from these twosources has been estimated as high as fifteen per cent. of the wholequantity of rags ground. Another objection to this engine is, that itsspeed is limited to a certain low rate from the fact that when theperiphery of the cylinder of the grinder begins to run above twelvehundred feet a minute, it repels the rags and water in such manner as toretard their entrance between the grinding knives, and when the speed ofthe cylinder is greatly accelerated, the current will be almost arrestedand the grinding stopped. This limit to the speed of the stud-engine, itwill be seen, is a very serious objection, when its great bulk and thelarge amount of floor space it occupies are taken into account, es-

' concentric with it and the cylinder.

pecially in manufactories doing an eXtensive business and requiring alarge number of these engines.

It is one of the objects of my invention to remedy the before mentioneddefects of the stuff-engine, and this I accomplish by providing in myimproved engine for the withdrawal of the fiber from the action of thegrinder, the moment it is sufficiently reduced, and leaving to be longeracted upon, that which requires more grinding, by which means, the wholeof the fiber, whether strong or weak, is reduced to pulp of uniformfineness, each part of it being subjected to a degree of grindingproportioned to its strength. Further, by rendering the feed independentof the motion of the grinder, the engine can be run at any speed thatits strength will sustain, and the work is thus done much more rapidlythan in the old engine, as the grinder can be run very fast and thehalf-stuff thoroughly reduced by passing through it once, and lastly, bydispensing with the annular vat and feeding the half-stuff| to theengine through a pipe and discharging the pulp therefrom by similarmeans, this engine is rendered very compact and requires less than onequarter of the space occupied by the engine hereto fore in use.

By reference to the accompanying drawings, the construction andoperation of the stuff engine to carry into effect my improved process,will more fully appear. It consists of a bed-plate (B) which supportstwo standards (A, A) anda hollow cylinder (C) whose diameter is equal toabout four times its length. In a line with the axis of this cylinder, ashaft (D) is mounted in bearings in the heads of the standards (A, A).In a bracket (c) on the outer standard (A), and in a boss at the middleof the outer head of the cylinder (C) set screws (Z9) are placed, in aline with the aXis of the shaft (D), the object of these setscrews is topermit the shaft (D) to have a regulated amount of end-play in itsbearings, for a purpose which will presently be described, or to adjustit for any special purpose, at any given point within the range of itsend-play. This shaft passes through a stuffing-box on the inner head (d)of the cylinder (C), and projects about two-thirds of the way across thespace within the cylinder, toward its outer head On this projecting endof the shaft (D) a disk (E) is secured at right angles with the shaftand This disk is somewhat less in diameter than, and in thickness abouthalf the length of the interior of the cylinder, so as to leave betweenit and the heads and periphery of the cylinder, a free space for acurrent of water and rags, half-stuff, or paper pulp to flow through.

The inner surface of the heads of the cylinder and the sides of thedisk,are grooved in the usual manner of metallic grinders, or they may bearmed with teeth or knives of any suitable kind. An orifice is made ineach head of the cylinder, as near the center as possible. The orificein the outer head (d) is connected by a pipe (F) with a tank abovecontaining half-stuff mingled with water and ready to be ground intopulp. With the orifice in the inner head (fl) a pipe (G) is connected,which conducts off to a proper receptacle, the pulp discharged from themachine.

Th-e operation of the engine is as follows. Rotary motion iscommunicated to the shaft (D) through the pulley near its middle, andthe set-screws (b) are so adjusted as to allow the shaft to play enoughto permit the disk (E) to run freely from end to end of the cylinder (C)to grind close at either end or open at both, as may be required, or ifit should so happen that the fiber is of uniform strength, and thehalf-stuff homogeneous, the disk (E) may be fixed in one position by theset-screws (b) as represented in Fig. l of the djrawings. The mixedhalf-stuff and water may now be let into the feed-pipe (F) from the tankabove, and the hydraulic pressure will force it into the cylinderthrough the space (e) between the disk and the outer head (cl), aroundthe periphery of the disk and through the space to the orifice of thedischarge pipe (Gr), where it will leave the cylinder, and entering thedischarge pipe, will pass through the same into any suitable receptacle.

The centrifugal motion of the disk will coperate with the hydraulicpressure to pass the half stuff from the feed orifice near the center,where the motion of the disk is slow and but little grinding takesplace, toward the periphery, where the motion is greater and thegrinding energetic, but when the current of water and fiber turns theperiphery of the disk, and enters the space (f) on the opposite side,its passage to the discharge orifice is retarded by the centrifugalaction of the disk. This retarding force acts with the greatest effectupon the largest fibers. Moreover, the current carries the fibersthrough the grinder at a speed inversely proportioned to their size, themore reduced fibers having an area of surface for the current to actupon, relatively far greater than that of the larger fibers. In this waythe reduced fibers are withdrawn from the action of the grinder, whilethe coarser fibers are left for further reduction. This separation ofthe finer from the coarser fibers, during the process of grinding, isfacilitated by the increased mobility which they acquire by reduction.

The fineness of the grinding, it will be seen depends upon the hydraulicpressure 1 on the feed and the speed with which the disk of the grinderruns, while t-he rate of feeding depends upon the pressure alone.

In case a knot or lump of fiber should be fed into the grinder, the diskwould, yield, moving toward the side opposite the knot, to allow theknot to pass freely toward the periphery, where it will be quicklyreduced by the energetic action of that part of the grinder. While thisreduction of the knot or lump is going on at the feed-side of thegrinder, both the feeding and discharge are diminished, by the crowdingover, by the knot of the revolving disk, against the discharge aperture;by this yielding of the disk, all danger of clogging is avoided, and atthe same time, the flow of unground ber through the grinder, isprevented. Further, if the ber is tender and easily reduced, it willflow freely through the grinder, and occupy but little more space on thefeeding than on the discharge side of the disk, but, if the fiber istough and grinds slowly, it will accumulate on the feed side and crowdthe disk over to the discharge side, retarding the discharge, the strongfiber being in this way subjected to, as it requires, more grindingaction than the weaker liber.

This machine is one I have devised for carrying my process into eifect,but it will be obvious to those skilled in the art of manufacturingpaper, that the modifications of machinery which might be constructed tooperate upon this principle would be very numerous indeed, and it wouldbe impossible even to enumerate them within the proper limits of aspecification. I will, however, mention one or two by way of example.

The cylinder and rotating disk might be elongated in the direction oftheir axes, so that instead of their diameters being greater than theirlengths, their lengt-hs might begreater than their diameters, and theperiphery of each might be armed with a grinding surface, leaving theends of both, unarmed. Again, the diameters of the ends of the revolvingand hollow cylinders might be reduced in such manner as to give to themthe proportions of the middle section of a spindle, or of two frustra ofcones, united base to base. Or, instead of being of a conical or spindleform, these parts may be made spherical.

Vhat I claim as my invention and desire to secure by Letters Patent is-The process of reducing fibrous matter, in water, to pulp by grinding itunder hydraulic pressure, which creates a current that feeds the iberinto the grinder, and removes it therefrom as fast as it is sufficientlyreduced and renders the feeding independent of the grinding,substantially as herein set forth.

In testimony whereof, I have hereunto subscribed my name.

JOSEPH KINGSLAND, JR.

In presence of- EDWARD MURPHY, L. C. STUART.

[FIRST PRINTED 1912.]

